What? You talking too much and mix up a lot of things.

I know what urea is. Obviously it's more important for you to put it in some other light, than to acknowledge it is a strong diuretic, which would support my OP. Also, talking about drinking distilled water, pure water.. I see some strong misconception of how our body works. Also the whole story with kidneys having a stress because there are some stones.. they are not under stress. They can't be under stress. It's not a muscle that uses up energy when put under stress. They produce and need water to dilute the concentrate so it can be watered out. There is not a time where kidneys do more work or less work. They always doing 100 percent. The amount of urea a body is producing, is driven heavily by protein intake and cellular things. So the kidneys are doing always 100 percent. They don't care if there's much waste or less. But what you have is a certain capacity called Urea clearance (ml/h) and also creatinine clearance. If your clearance is lower than the intake or metabolism, then you need some diuretica in the beginning to water out as much water as still possible and later, if it's not sufficient anymore, dialysis.

When you have damaged kidneys, it's not like a motor that is stuck. It's rather the damage of the glomerulus', which can be physically provoked by too much of (big) protein molecules that are being water out (bodybuilding, >120g per day for a few months for example will surely lead to kidney problems), be caused by bacterial infections which cause inflammation and that causes scars in the material, or may be caused by some other kidney illnesses.

Stones are known of two different kinds to exist. One is calcium stones and the other oxalate stones. Both have different causes. You have to take that into account :)

So, I don't quite get your story. It's so messy, if I say so. Different facts are mixed together without considering. That Belgian student died of too much salt. Which also will happen if you drink a few liters of salty sea water over a few days. The reason for this is osmolarity. If you have too much salt in your body, the osmolarity will pull water out of the body cells. The inner cell metabolism changes as result. One _might_ get problems. Or, if it was too much salt, one _will_ get problems. That's also a reason for being thirsty. Our body signals us to dilute it. The opposite will happen if you drink distilled water. That usually has less of minerals and ions. Again,the osmolarity will be on the side with the higher concentration of ions -> water will be pulled into cells which have and need salt for inner workings. The cells will burst because of (osmolarity) pressure.

If your kidneys slowly stop working (actually, it's logarithmic.. first slowly, later accelerated) you'll become thirsty. This is caused by too much of urea in the blood. As urea is a strong diuretic, the body needs more water to be able to water it out. But the levels of urea won't sink so fast anymore then..
And then you have problems with your blood pressure regulation. And .. and .. and ..
...

And so on.. there is much more behind that than the holy book you mentioned suggests. May be you should read it ;)